HARRIS COUNTY, Texas — A helmetless motorcyclist was killed Thursday morning after he crashed into a highway on ramp, the Harris County Sheriff’s Office said.

Investigators said the motorcyclist was going northbound on the 6000 block E. Sam Houston Parkway feeder road around 2:20 a.m. when he tried to take the entrance ramp.

Deputies said the driver didn’t see the curb that separates the feeder road and the entrance ramp, and struck the curb at full speed. The motorcyclist lost control of his bike, was thrown from the vehicle and he rolled several times, officers said.